Tissue removal by directing an air stream carrying an abrading agent (such as corundum crystals) onto human skin has been known, as disclosed, for example, in U.S. Pat. Nos. 5,037,432, 5,100,412 and 5,810,842.
Surface skin tissue removal may be indicated for various skin conditions, such as scars, wrinkles, abnormal pigmentation, stretch marks, tattoos, burns, etc.
It is a common characteristic of the prior art constructions to supply the abrasive-laden air stream to the handpiece by a flexible pressure line leading from a mixing bulb which has a capacity of, for example, one or two pints. Compressed air is introduced into the mixing bulb which accommodates the abrasive crystals (having a grain size of, for example, 120 micron). The air stream carries the abrasive crystal from the mixing bulb through the pressure line to the handpiece, and the operator manually guides the handpiece in gentle contact with the skin surface, whereby the skin is being bombarded by the abrasive crystals as they exit through a handpiece opening facing and being generally obturated by, the skin surface.
After impinging on the skin, the abrasive crystals, entrained by a low-pressure (vacuum) air flow, immediately re-enter the handpiece together with the dislodged skin particles and exit from the handpiece through a vacuum leading into a collecting bulb which also may be of a one-pint capacity, and which may be situated adjacent the mixing bulb. The collecting bulb is coupled to a vacuum source so that a continuous closed flow is maintained to continuously pelt the skin surface with fresh abrasive crystals from the mixing bulb supplied by the pressure flow and then immediately withdraw the used crystals and dislodged skin fragments in the vacuum flow.
Like for any medical instrument, sterilization of the handpiece and the collecting bulb before reuse has been a principal consideration. Also, strict measures have to be taken to maintain both the mixing bulb and the collecting bulb well isolated from the environment. These requirements involve stringent and involved measures, particularly when the apparatus is used in the field.